Motor-controller



T- E. BARNUM.

MOTOR CONTROLLER.

APPLICATION FILED JUNE 21, 1911.

Patntd Mar. 30, 1920.

UNITED STATES PATENT OFFICE.

THOMAS E. BARNUM, OF MIIIZ'WA'CI'KEIIEI, WISCONSIN, ASSIGNOR TO THECUTLER-HAMMER MFG. 00., OF MILWAUKEE, WISCONSIN, A CORPORATION OFWISCONSIN.

MOTOR-CONTROLLER.

Specification of Letters Patent.

Patented Mar. 30, 1920.

Application filed June 21, 1917. Serial No. 176,021.

ularly to controllers having alternating current operating meansadapting the same for remote control.

The present invention has among its objects to provide a controller ofthe aforesaid type which will obviate the noise of operation andsubsequent hum or chatter which results from the employment of A. C.electromagnets and solenoids and which is often so objectionable thatwhere quiet is demanded, as in hospitals, the use of such op-' eratingmeans is impractical.

A further object is to provide a quietly operable controller wherein asingle torque motor will serve to effect numerous func tional operationsand will moreover serve to give phase failure protection.

A still further object is to provide a reversing controller wherein asingle torque motor will serve to effect both reversing and acceleratingoperations and will moreover serve to give phase reversal protection.

Various other objects and advantages of the invention will hereinafterappear.

The accompanying drawing schematically and diagrammatically illustratesone embodiment of the invention which will now be described, it beingunderstood that the invention may be embodied in other forms fallingwithin the scope of the appended claims.

Referring to the drawing, the controlled motor M is of a three phaseslip ring type to be supplied with power from lines L, L and L and to beaccelerated through the medium of sets of resistances R, R and Rconnected in its rotor circuit in the usual manner.

The reversing means comprises two triple pole switches 1 and 2 operableselectively by reverse movements of a shaft 3 through the medium of cams4: and 5 which respectively coact with rollers on crank arms 6 and 7operatively connected to the movable elements of the two switches. Morespecifically, each switch comprises three contact arms a, b and 0adapted to cooperate with stationary contacts-a, Z) and 0' respectively,said arms being fixed to and insulated from a common shaft 8 and saidshaft also having fixed thereto one of the cam operated arms abovedescribed.

The switches 1 and 2 serve to reverse the connections between two of thesupply lines and two of the motor terminals as hereinafter specified andthe cams 4 and 5 are constructed to permit continued rotation of theshaft 3 for a purpose hereinafter set forth followin the closure of theselected reversing switc The accelerating means comprises three pairs ofswitch arms 10-10 1111 and 1212 coopera'ble with contacts 13-13",14r.-1l and 15-45 to short circuit the resistance R, R and Rrespectively by well known connections. The three pairs of switch armsare yieldingly mounted in a well known manner upon an oscillatable shaft16 and insulated from one another, said pairs of arms being set atdifferent angles upon said shaft to be moved progressively intoengagement with their respective contacts upon clockwise rotation ofsaid shaft, the latter being so operable by shaft 3. More specifically,the shaft 16 has fixed thereto a crank arm 17 connected by a pin 18 toalink 19, which is connected at its up per end to a crank arm 20 fixed toshaft 3. With both reversing switches open the link 19 and crank arm 20are alined whereby rotation of shaft 3 to operate either reversingswitch also lifts said link to rotate shaft 16, the arrangement,however, being such as to insure against closure of any acceleratingswitch until after closure of the selected reversing switch.

Conversely upon return rotation of the shaft 3 the link 19 is forceddownwardly to rotate the shaft 16 in a counter-clockwise direction torelease the accelerating switches, which then automatically move to openpo sition. Further, the shaft 16 is shown as provided with a dash pct 21to oppose its clockwise movement and to thereby provide a time elementin the exclusion of the accelcrating resistances. This dash pot ismounted upon a tail piece of the crank arm 17 and for convenience ofillustration the piston of the dash pot has been shown as connected tothe shaft 3 by a member 22.

A torque motor M is provided to operate Further, it will be observedthat should the supply line be subject to a phase reversal the shaft 3for closure of the switches described, subject to return of said shaftby .a spring 2 1 upon a given reduction in the torque of said motor,said spring having one end connected to a fixed part and its'oppositeend connected to a crank arm 25 fixed to shaft 3. The motor M is of thesquirrel cage type and is of the same number of phases as motor M. Also,as will hereinafter appear, it is connected through a master switch 26to the supply circuit whereby it is subject to the same phase reversalsas the motor M.

Thus the torque motor provides for selective operation of the reversingswitches and also for operation of the accelerating switches andmoreover provides for quiet operation of all of said switches and firmretention thereof in closed position.

The master switch 26 comprises a manually operable arm having twoinsulated contact sections 27 and 28, the former to continuously engagea segment 29 and to engage selectively contacts 30 and 31 and the latterto continuously engage a segment 32 and to engage selectively contacts33 and 3 1. The segments 29 and 32 are respectively connected to twoterminals of themotor M, the third terminal of said motor being directlyconnected to line L, while contacts 30 and 33 are connected to line Land contacts 31 and 34 to line L. Accordingly it will be observed thatthe switch 26 serves to complete the circuit of motor M and to reversethe connections between two terminals thereof and lines L and L toeffect operation of said motor in either direction at will, that is,assuming a constant phase relation. For example, it may be assumed thatclockwise movement of the controller effects clockwise rotation of theshaft 3 and consequent closure of reversing switch 2 for clockwiserotation of motor M and that reverse movement of the master controllereffects counter-clockwise rotation of the motor M and shaft 3 to closethe reversing switch 1 for counter-clockwise rotation of motor M.

with the result of efiecting counter-clockwise operation of motor M uponclosure of reversing switch 2 and clockwise rotation of said motor uponclosure of reversing switch 1, such phase reversal would also causemotor M to operate in a reverse manner relative to the master switch.For example, should the master switch then be moved to the right themotor M would operate in a counter-clockwise direction thereby closingreversing switch 1 instead of switch 2 as previously described, with theresult of insuring clockwise operation of motor M, or in other words,rotation in the same direction as though no phase reversal had occurred.On the other hand, should the master switch follows Assuming stalls andduring continuance of normal torque holds the selected reversing switchandaccelerating switches in closed position. On the other hand, uponrestoration of the master switch to off position, or upon a given dropin voltage, the motor M releases the shaft 3 whereupon the springrestores thereby releasing both the reversing switch and theaccelerating switches. This proi said shaft to the angular positionillustrated,

vides for interruption of the circuit of the.

motor M and for reinclusion of the resistances R, R and R whereby themotor is insured protection in restarting. Further, should a phasereversal occur after setting of the controller for operation of themotor in either direction the motor M would be e. ed and would assistthe spring 24 to release both the'selected reversing switch and theaccelerating switches. Also, it would fur-- ther act to at once closethe other reversing switch and reclose the accelerating switches torestart the motor in the direction last selected by the master switchwith only a momentary interruption of the circuit of said motor.

The connections of the main motor are as closure of reversing switch 1,line L is connected by conductor 36 through arm a and contact a of saidreversing switch, by conductor 37 to the left hand terminal of saidmotor; line L by conductor 38 through arm 6 and contact I) by conductor39 to the center terminal of said motor, and line L by conductor 40through arm 0 and contact a by conductor 41 to the right hand terminalof said motor. On the other hand, assuming closure of reversing switch2, the left hand terminal of the motor is connected through contact arma and contact a to line L, while the other two terminals of the motorare reversed with respect to contacts L and L Line L is then connectedthrough arm I) and contact I) by conductor 41 to the right hand terminalof said motor, while line L is connected through contact arm 0 andcontact 0 by conductor 39 to the center terminal of said motor.

What I claim as new and desire to secure by Letters Patent is:

1. In a controller for alternating current motors, incombination,reversing means, a celerating means and an alternating current motor foroperating both of said means and holding the same against returnmovement.

2. In a controller for alternating current motors, in combination,reversing means, accelerating means, an alternating current motor andoperative connections between both of said means and said motorproviding for operation of said means progressively by said motor, bothof said means being adapted to return to their initial positions uponrelease thereof by said motor.

3. In a controller for alternating current motors, in combination,reversing switches, a rotatable shaft having cams to actuate saidswitches selectively upon oscillation of said shaft, acceleratingswitches operatively connected to said shaft to be actuated thereby butsubject to prior operation of said reversing switches and an alternatingcurrent torque motor operatively connected to said shaft for operatingall of said switches and holding the same closed.

4. Ina controller for alternating current motors, in combination,reversing switches,

a rotatable shaft having cams to actuate said switches selectively uponoscillation of said shaft, accelerating switches operatively connectedto said shaft to be actuated thereby but subject to prior operation ofsaid reversing switches, a dash pot for retarding operation of saidaccelerating switches, and an alternating current torque motoroperatively connected to said shaft for operating all of said switchesand holding the same closed.

5. The combination with a polyphase alternating current motor andpolyphase supply circuit therefor, of means controlling the continuityof circuit of said motor and the direction of operation thereof,accelerating means for said motor and common electromagnetic operatingmeans for both of the former means to effect progressive operationthereof, said electromagnetic means being responsive to supply-circuitphase reversals for insuring against reversals of said motor thereby. p

6. The combination with a polyphase a1- ternating current motor andpolyphase supply circuit therefor, of means controlling the continuityof circuit of said motor and the direction of operation thereof,accelerating means for said motor, common electromagnetic operatingmeans for both of the former means to effect progressive operationthereof, said electromagnetic means being responsive to supply-circuitphase reversals for insuring against reversals of said motor thereby andmeans controlling said electro magnetic means to effect reversal of saidmotor at will.

7. The combination with a polyphase al-,

ternating current motor and polyphase supply circuit therefor, of acircuit controlling device for said motor to start and stop the same andto effect reversal thereof, an accelera-ting device for said motor, apolyphase motor operatively connected to said devices I to actuate thesame progressively and to opto actuate the same progressively and to op-I erate said first mentioned device in opposite directions for reversalof said first mentioned motor, and a reversing switch and clrcuitconnections for said second mentioned motor whereby the selection ofoperation of said first mentioned motor may be selected by said switchirrespective of supply circuit phase reversals.

9. In a motor controller, in combination, means to control thecontinuity of the motor circuit and to-efiect reversals of the motor,

accelerating means, and a single torque motor operatively connected toboth of said means to effect operation thereof progressively for reverseoperations of the controlled motor, both of said means being .biasedagainst operation by said torque motor and being dependent for retentionin operative positions upon continued torque of said motor.

10. In a motor controller, in combination, reversing switches for themotor, a common operating shaft therefor having cams thereon to actuatesaid switches selectively upon rotation of said shaft in oppositedirections, said shaft being thereupon capable'of continued rotation,accelerating switches, means operatively connecting said acceleratingswitches and said shaft for operation of the former by rotation of thelatter in either direction but only after operation of the selectedreversing switch, said shaft being biased to release all of saidswitches and a torque motor for operating said shaft in oppositedirections against itsbias for selective operation of said reversingswitches and progressive operation of said reversing'and THOMAS E.BARNUM.

